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New Member

3550 & 4006 trunk link is not allowing ping or telnet on native vlan 1 ???

Hello all, I have set up a 3550 (SMI) switch on int gig0/1 as a 802.1q trunk . I left the trunk mode in the default mode of desirable auto. It plugs into a 4006 on slot 6/1 (SX multimode GBIC) which is also configured as a trunk mode on and ecap. dot1q. The VTP domain is configured w/ password and both are showing vtp advertisements. From the 3550 48 10/100 ports I have set switchport access vlan 50 which makes those 48 ports static-access ports correct ?? Anyway, I can plug in my laptop and go dhcp to that particular subnet range and successfully obtain an ip address on vlan 50 due to the fact that on the 4006 I have the ip helper-address pointing to that server, this works fine but the mgnt. IP address I put on the 3550 is in a different subnet and I can't ping or telnet to the 3550 from beyond the trunk. Does anyone know how I can fix this config to where I CAN ping and telnet to the mgnt. IP address on vlan 1 in the 3550 switch?

Here is a bit of the 3550 config.....

CCW-IDF#2-CSW1#show int gig0/1 switchport

Name: Gi0/1

Switchport: Enabled

Administrative Mode: dynamic desirable

Operational Mode: trunk

Administrative Trunking Encapsulation: dot1q

Operational Trunking Encapsulation: dot1q

Negotiation of Trunking: On

Access Mode VLAN: 1 (default)

Trunking Native Mode VLAN: 1 (default)

Trunking VLANs Enabled: ALL

Pruning VLANs Enabled: 2-1001

Protected: false

Unknown unicast blocked: disabled

Unknown multicast blocked: disabled

Voice VLAN: none (Inactive)

Appliance trust: none

CCW-IDF#2-CSW1#

CW-IDF#2-CSW1#show int gig0/1 trunk

Port Mode Encapsulation Status Native vlan

Gi0/1 desirable 802.1q trunking 1

Port Vlans allowed on trunk

Gi0/1 1-4094

Port Vlans allowed and active in management domain

Gi0/1 1,48-55,80,220

Port Vlans in spanning tree forwarding state and not pruned

Gi0/1 1,48-55,80,220

CCW-IDF#2-CSW1#

Here is the capture from the 4006 slot 6/1 (SX GBIC)

CORE-A> (enable) show trunk 6/1

* - indicates vtp domain mismatch

Port Mode Encapsulation Status Native vlan

-------- ----------- ------------- ------------ -----------

6/1 on dot1q trunking 1

Port Vlans allowed on trunk

-------- ---------------------------------------------------------------------

6/1 1-1005

Port Vlans allowed and active in management domain

-------- ---------------------------------------------------------------------

6/1 1,48-55,80,220

Port Vlans in spanning tree forwarding state and not pruned

-------- ---------------------------------------------------------------------

6/1 1,48-55,80,220

CORE-A> (enable)

CORE-A> (enable) show port 6

Port Name Status Vlan Level Duplex Speed Type

----- ------------------ ---------- ---------- ------ ------ ----- ------------

6/1 connected trunk normal full 1000 1000BaseSX

Thanks in advance,

~ ZO

6 REPLIES
Silver

Re: 3550 & 4006 trunk link is not allowing ping or telnet on nat

Zo

Make sure that you have at least 1 port configured and active in vlan 1 on both switches

New Member

Re: 3550 & 4006 trunk link is not allowing ping or telnet on nat

I have int vlan 1 on the 3550 configured with the mgnt. IP address. Doesn't that mean that int vlan 1 IS in vlan 1?? The 4006 already meets this criterea.

Silver

Re: 3550 & 4006 trunk link is not allowing ping or telnet on nat

a physical port must be assigned to that vlan

New Member

Re: 3550 & 4006 trunk link is not allowing ping or telnet on nat

All right, I'll give it a shot and let you know how it goes. Thanks :-)

New Member

Re: 3550 & 4006 trunk link is not allowing ping or telnet on nat

By the sound of things you have a L3 routing problem. I'm assuming that the mgnt IP addresses of both 4006 and 3550 are on the same subnet? If so then they should be able to ping each other. If not then you have trunking and VLANs allowed on trunk issue. You might also want to check that there is a default gateway/default router setup on your 3550. Since you're using SMI, I'm guessing that you'll need to setup only default gateway. BTW, if two switches can ping each other (using typically VLAN1) AND the 4006 is pingable from the PC (which is on a different subnet) BUT the 3550 is NOT pingable (from the PC) then most likely you have not setup a default gateway on it. Let me know how you go. Cheers

New Member

Re: 3550 & 4006 trunk link is not allowing ping or telnet on nat

Yes, it was a routing problem. I figured it out yesterday. The mgnt. IP address on the 4006 was in a different VLAN (not vlan1). The thing that threw me off was that YES both the 3550 and the 4006 had 2 mngt IP's in the same subnet, but I didn't have it set up on vlan1 in the 4006. So at first glance I saw that both switches were configured with correct subnet IP's, but when I took a closer look I realized that I needed to go into the correct int vlan config mode and assign the correct vlan an IP in the same subnet. This kind of means that my VLAN 1 is not my TRUE mgnt vlan anymore. Is this bad?

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